Energy Device Options – Strategies to Prevent InjuryEnergy Device Options – Strategies to Prevent Injury Dean J Mikami, MD. FACS ... resistance Properties of Electricity Current

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Energy Device Options – Strategies to Energy Device Options Strategies to Prevent Injury

Dean J Mikami, MD. FACSAssociate Professor of Surgery

Center for Minimally Invasive SurgeryThe Ohio State University

Program Content

• Basics of Electricity

• Principles of Electrosurgery

• Clinical Applications

• Electrosurgical TechnologiesElectrosurgical Technologies

• Associated Risks

• Recommendations for Safe Practices

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Electrosurgical Injuries

• AORN estimates c. 40,000 patients burned by faulty ES devices per yeary p y

• Up to 70% of ES burns in laparoscopic surgery may be undetected at the time of injury

• ACS survey: 18% of surgeons had experienced insulation failure or capacitive coupling injury, 54% knew a colleague who had a stray electrical burnknew a colleague who had a stray electrical burn

• In 1999, nearly $600 million paid in claims re ES injuries

Source: Outpatient Surgery Feb 2002

Two Types of Energy Used in Surgery

Electromagnetic Energy Mechanical Energy

– Electrosurgery

• Monopolar Electrosurgery

• Bipolar Electrosurgery

– Laser

–Suturing

–Stapling

–Ultrasonic (Ultrasound)

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Basic Principles of Electricity

Electricity always . . .

– Seeks ground (its source)

– Seeks the path of least resistanceresistance

Properties of Electricity

Current Flow of electrons during a period of time, measured in amperes

Circuit Pathway for the uninterrupted flow of electrons (must be complete/ closed to flow)

Impedance Obstacle to the flow of current measured in ohms

Voltage Force pushing current through the resistance, measured in volts

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AC current at frequency of 60frequency of 60

Hertz (Hz)

FUSEFUSELOGOLOGO

AC current at frequency of 60frequency of 60

Hz

Faradic Effect= muscle contraction, cardiac interference,

etc.

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FUSEFUSELOGOLOGO

350 kHz to 4 MHzNo Faradic effect

Electro Surgical Unit

Frequency Spectrum

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Electrosurgical Unit:Patient Protection Measures

• Inspect for any damage

• No fluids on top of unit

• Do not use in presence of flammable material (e.g. alcohol, nitrous oxide)alcohol, nitrous oxide)

• Patient not in contact with any metal objects

Generator (ESU) Power Settings

• Use the lowest possible setting to achieve the desired surgical effect

• The setting will depend upon conditions such as:

– Patient size

– Generator power capabilities

– Target tissue type

– Electrode configuration

– Surgeon Technique

– Location of patient return electrode

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Dispersive Electrode Guidelines

• Contact with patient must be uniform over large surface area

• Avoid the following:– Bony prominences

– Metal implants or prosthesis

– Scar tissue

– Hairy areasHairy areas

– Adjacent to leads/electrodes

– Pressure areas/points

• Never cut to size

Electrode Size and Effect on Power Settings

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Current Concentration/Dispersal

The more concentrated the current, the greater the potential for a burn.

Patient Burns

Pad site burn

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MonoPolar Monopolar InstrumentsActive Electrode

Patient

Low Voltage (“Cut”) “Pure”

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El t d 1

Dispersive Electrode

High Voltage (“Coag”)0

Electrode 1

Electrode 2

Monopolar

• Active electrode at surgical site

• Return electrode at another site

• Current flows through the body between the electrodes

• High voltageg g

– Coag – 3000 – 9000 V

– Cut – 1350 – 4000 V

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Mushroom EffectAs the tissue desiccates Impedance Increases

Waveforms(Blend is a CUT mode)

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Direct Coupling

• Occurs when one conductive source touches or arcs to another

1. Current may be directed toward non-target tissue

2. Instrument in contact with active electrode may not be completely in view (laparoscopic case) and/or contacting other tissue (bowel or abdominal wall)

Capacitive Coupling

• Capacitance: defined as stored electrical charge when two conductors separated by an insulator

• Capacitive coupling current occurs when the circuit is completed through the dielectric (e.g. insulator)

• Charge stored in capacitor until either generator is deactivated or pathway to complete circuit is achieved

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Alternate Site Injuries

• Current delivered must return to generator

• Much less common today with isolated generators (will not deliver more current to electrode if not enough current returns to generator, i.e. leaves via an alternate site)

• Precautions: patient should not be in contact with any objects with high conductivity

Inadvertent Activation

• Beware of creating an injury out of field of view (blind instrument insertion or inadvertent electrode application)

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Direct Thermal Extension

• Duodenum often adherent to or in close proximity toto or in close proximity to gallbladder

• Use short activations of electrode (2-3 sec)

Beware the adhesion with• Beware the adhesion with narrow attachment to duodenum

Adhesions between GB and duodenum

Surgeon Burns/Surgical Glove Injuries

• Holes are present in 15% f i l15% of new surgical gloves and in ½ after use in surgery

• Capacitive coupling from sweating skinfrom sweating skin inside surgical glove

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Surgeon Burns/Surgical Glove Injuries:Mechanisms of Injury

1. High voltages across glove (dielectric) break insulating capacity of glove

2. Decreased glove resistance (with time and exposure to saline (sweating)

3. Capacitive coupling – risk inversely proportional to glove thickness and increases with higher voltage and g glonger contact time (active electrode and touching hemostat)

Helpful Hints to Avoid Hemostat Burns

• Use lowest power setting possible

• Activate low voltage (cut) waveform

• Avoid touching the patient

Hold hemostat with full grip• Hold hemostat with full grip

• Do not activate in open circuit (avoid metal to metal arcing)

Note: Surgical gloves do not insulate against RF current

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Bipolar

• Active and return electrodes in theelectrodes in the instrument

• Current flow confined to tissue between electrodes

• Low Voltage

– 320 - 1200 volts

BipolarLow Voltage (“Cut”) “Pure”

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Patient

High Voltage (“Coag”) 0

30

Electrode 1

Electrode 2

Two Active Electrodes

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Bipolar

• Benefits:

• Doesn’t Require Dispersive Electrode

• Energy Primarily stays between the Jaws

• Requires less Voltage and Current (“cut” waveform)Requires less Voltage and Current ( cut waveform)

Limitations of Traditional (simple) Bipolar

• Continuous, uninterrupted delivery of energy

• Surgeon controls the delivery of energy visually

• No feedback mechanism to determine impedance ( thermal Spread, carbonization)

Promotes e cessi e thermal damage• Promotes excessive thermal damage

• Devices coapt tissue poorly

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Modern Advance Bipolar Technology

– Smart Generator Technology

• Near real-time Impedance feedback from delivery device

• Pulsing (rapid on/off) energy delivery– Allows for interval tissue cooling

• Audible signal indicates adequate coagulation

• Vessel up to 7 mm vessels

Best Practices

• No tension– Let the instrument do its job– Let the instrument do its job

• Keep Jaws Clean: – Never activate with coagulum build-up on the

inside of the jaws.

• Vessels up to 7 mm– Be careful of calcified vessels.

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Best Practices

OVERLAPPING SEALS:– Consider overlapping seals in areas of anatomical– Consider overlapping seals in areas of anatomical

tension.– When overlapping seals, do so by 30-50%.

• Knife blade damage– Do not attempt to fuse or cut over clips, staples or

sutures

– Do not use the knife for cutting suture

Thermal Spread with Bipolar

• With Modern Bipolar Instrument– Seen with all electrosurgical instruments

– Tissue damage occurs at 60 degrees Celsius

– Range 1-4 mm

– Be aware of residual heat.

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Ultrasonic Technology: The Hand Piece

Electrical energy from the generator

MECHANICAL MOTION VIDEO

is converted to mechanical motion in the hand piece

Piezoelectric ceramics Mount Mechanical Wave

Actions of Ultrasound on Tissue

CoagulationCutting Cavitation

All surfaces of the ultrasonic blade are active.

BACK SCORING/DRILLING VIDEO CAVITATION VIDEO

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Factors affecting cutting and coagulation

1. Blade pressure

2. Tissue tension

3. Power level

4. Blade sharpness

Blade activation temperatures

ULTRASONIC

BIPOLAR

0 50 100 150 200

°c

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Thermal Spread

Blade activation temperatures

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Benefits and Risks of Ultrasonic Coagulation

V l l d ld d t th• Vessels are sealed or welded together

• Minimal spread of energy, but the blade is HOT

• Coagulum does not stick to blade

• Minimal smoke generation more water vapor

• No neuromuscular stimulationNo neuromuscular stimulation

• Uniformly coagulates 5mm vessels

Current Leakage

• Active electrode cords sho ld not be rappedshould not be wrapped around metal instruments

• Active electrode and other electrical device

d h ld bcords should not be bundled together

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Pacemakers

• Consult pacemaker manufacturep

• Use electrosurgery with care

• Use ultrasonic technology

• Use low power setting (bipolar)

• Avoid current flow through heart and pacemaker

• Keep cords away from pacemaker and leads

AORN Recommended Practices 2009

Automatic Implantable Cardioverter Defibrillators

• Use of Electrosurgery on a patient ith anon a patient with an activated AICD may trigger an electrical shock to the patient

• The AICD device should b d i d b fbe deactivated before the ESU is activated

AORN Recommended Practices 2009

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Active Electrodes

• When not in use, always place active electrodes in a non-conductive holster

• Active electrode tips should be securely seated into the hand piece (increase risk of sparking or burn to targeted tissue)

AORN Recommended Practices, 2009

Smoke/By-products

• Types of products from electrosurgery

– Toxic vapors and gases (e.g. benzene, hydrogen cyanide, formaldehyde)

– Chemicals and irritants (potentially mutagenic or carcinogenic)

– Bioaerosols including blood fragments

– Viruses

– Methemoglobin and carboxyhemoglobin in laparoscopic surgerysurgery

• Surgical masks filter size = 5 microns, 77% of surgical smoke contents are 1.1 microns or smaller

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Effects of Smoke/By-products

• High concentrations of smoke cause ocular and upper g pprespiratory irritation in health care personnel. – Note: No documentation of cancer cases from OR

smoke exposure.

• OSHA recommendation: smoke evacuation systems should be used to reduce acute and chronic risks to patients and health care personnelp p

.Source: AORN 2005;81:616-642DHHS Pub 96-128 (OSHA), Sept 1996

Fire Hazard

• Do not activate ignition so rces in the presence ofsources in the presence of flammable agents

• Avoid pooling of prep

• Drape patient after vapors ape pa e a e apo sfrom flammable agents have dissipated

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OR Fires

• Rare but potentially devastating

• ECRI estimate: 550-650 cases/yr (similar to # wrong site surgery cases)

• 95% are minor and result in no injury

• 20-30 serious with disfiguring or disabling injuries

ECRI Institute is an independent, nonprofit organization that researches the best approaches to improving the safety, quality, and cost-effectiveness of patient care.

Why is it important?

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OR Fires: Fire Triangle

• Fire triangle: – Heat source (ESU lasers)Heat source (ESU, lasers)

– Fuel (drapes, prep)

– Oxidizer (O2, N2O)

• 21% occur in the airway, 44% head, neck, face or upper chest

• Ignition sources:ES equipment 70%– ES equipment - 70%

– Lasers - 10%

Modified from Health Devices Oct 2009

Explosions

• Significant risk in ether/cyclopropane era (even from static discharges)from static discharges)

• Electrosurgery risk with unprepped bowel

– Hydrogen-air mixtures btn 4-7% and methane btn 5-15% potentially explosive

A id it l f b l ( t– Avoid mannitol for bowel prep (promotes production of methane)

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Prevention: When Using Electrosurgery

• Minimize use of open O2 (via mask or cannula) for head and neck procedures

• Be aware of O2 enrichment under drapes (esp head and neck procedures)

• Tracheostomy: Use cold instruments to tracheal rings and enter the airway

• Do not apply drapes until flammable preps have fully dried; soak up spilled or From Health Devices Octp p y p ppooled age

• Connect fiberoptic light cable before activating source; standby source before disconnecting

From Health Devices Oct 2009

What to Do if OR Fire Occurs

1. Stop flow of all airway gases to patient (disconnect breathing circuit)breathing circuit)

– For airway fires, disconnect breathing circuit from tube and remove ET tube

2. Immediately remove burning and burned materials from patient (whether on or in the patient).

3. Extinguish the fire on burning materials (CO2 fire3. Extinguish the fire on burning materials (CO2 fire extinguisher rarely necessary)

4. Care for the patient– Restore breathing (use room air, never O2), manage pt

injuries

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Conclusion

• Understanding the fundamentals of i l (FUSE) i O tisurgical energy (FUSE) in Operating room

is everyone’s responsibility

• SAGE’s has initiated the FUSE program which is modeled after FLS and FESwhich is modeled after FLS and FES.